Environment/Reflection Map on model howto?

Hello you lovely people

How would I go about creating a shading network that would simulate an environment map on this Dalek model? I’d like to use my specular map texture as a mask ie the environment map is visible on the shiny paint but not on the dull scratched metal.

thanks in advance

This is a job for BeBraw’s Material ID pass which was unfortunately left out of Blender 2.46 (he told me the devs didn’t have time to review his code). this means that you will either have to split the sphere and render it as 2 seperate objects or create a mask (on it’s own render layer) and use that to alpha one sphere over the other (one sphere with env map on one render layer and another without env map on another render layer. Use common scene lighting on a separate scene layer (but common to all render layers) to tie these objects together for final composite.